The present invention relates to a rolling bearing and a cage for the rolling bearing, and more particularly, relates to the rolling bearing and the cage for the rolling bearing in which lubricating performance has been improved.
A rolling bearing provided with a plurality of rolling elements which are disposed between two rings, namely an inner ring and an outer ring, and a cage for holding these rolling elements has been well known. It has been an object to improve lubricating performance of the rolling bearing, in case where this rolling bearing is used in a machine tool which rotates at high speed, for example. In JP-A-2005-3145, it is proposed to change a shape of the cage for the purpose of improving the lubricating performance of the rolling bearing.
In the above described conventional rolling bearing, in case where the inner ring rotates, lubricating oil which has been supplied tends to be scattered outward in a radial direction by a centrifugal force. Consequently, it is difficult to retain the lubricating oil on a raceway surface of the inner ring, as rotation speed of the inner ring becomes higher, and such inconvenience that the rolling bearing burns out due to lack of an oil film is likely to occur.